1. Field of the Invention
The present invention relates to a C-type welding robot gun holding apparatus, particularly to an apparatus for fixing an equalizer when a C-type welding robot gun is free from operation.
2. Prior Art.
A conventional apparatus for fixing the equalizer when the C-type welding robot gun is free from operation is typically illustrated in FIGS. 2 and 3.
In the first conventional apparatus as illustrated in FIG. 2, a bracket 23 is fixed to a tip end of a robot wrist 21 for holding a fixing cylinder 22 and stopper holding members 25 and 26 protrude from a middle portion and a rear end of a pressure cylinder 24. Stoppers 27 and 28 are held by the stopper holding members 25 and 26 in which a rod 30 of the fixing cylinder 22 is permitted to bring into contact with the stopper 27 while a rear wall 29 of the bracket 23 is permitted to bring into contact with the stopper 28. When the C-type welding robot gun 31 is free from operation and is moved by the robot, a rod 30 of the fixing cylinder 22 extends to bring into contact with the stopper 27 while the rear wall 29 brings into contact with the stopper 28 whereby the C-type welding robot gun 31 is fixedly held by the robot.
In the second conventional apparatus as illustrated in FIG. 3, a hollow square stopper holding member 42 is fixed to a tip end of a robot wrist 41 and has front and rear walls 43 and 44 provided with stoppers 45 and 46. A pressure cylinder 47 has a protruding portion 48 to which a fixed arm 49 and a fixing cylinder 50 are fixed. A rod 51 of the fixing cylinder 50 is permitted to bring into contact with the stopper 45 while the protruding portion 48 is permitted to bring into contact with the stopper 45. When a C-type welding robot gun 52 is free from operation and is moved by the robot, the rod 51 extends to bring into contact with the stopper 46 while a front surface 53 of the protruding portion 48 brings into contact with the stopper 45 whereby the C-type welding robot gun is fixedly held by the robot.
However, there was such a problem in the first conventional apparatus that the interval between the stopper holding members 25 and 26 becomes long which results in rendering the pressure cylinder 24 longer since the C-type welding gun 31 is fixedly held by the robot in association with the stopper holding members 25 and 26 which are protruding from the middle portion and the rear end of the pressure cylinder 24 for holding the bracket 23 provided at the tip end of the robot wrist 21 and the fixing cylinder 22.
In the second conventional device, there was such a problem that the C-type welding robot gun 52 is bulky in height since the C-type welding robot gun 52 is fixedly held by the robot utilizing the stopper holding member 42 and the protruding portion 48 of the pressure cylinder 47 which renders the fixing arm 49 to dispose at higher position.